A block is a mechanism in a blockchain that contains a list of transactions and other relevant data, securely linked to previous blocks to form a chain. A reverse block, on the other hand, is not a standard term in blockchain technology; it may refer to a scenario where a previous block is effectively “undone” or invalidated, often due to a fork or a consensus change in a blockchain network.
This can lead to the creation of an alternative version of the blockchain, which may affect transaction validity and crypto exchanges network state.